The amazing aerial acrobatics of swifts

It happens usually in the second week of May, between about the 8th and 12th (this year it was earlier, the 2nd): a distant sound, building as it approaches, and then the doppler dip as the first of the returning swifts screeches past the roof of our Cornish farmhouse. It’s the opening bracket of the summer months, one that closes with their departure just 12 weeks later. But it is a reminder, too, that while we might think of our house as home to two adult humans, two teenagers and a dog, it is also the habitat for several nesting swifts, swallows, house sparrows, pipistrelle bats, mice, occasional winter rodents and all manner of buzzing, creeping invertebrates, as well as the billions of microbes and bacteria that survive our admittedly liberal regime of cleaning.

Mark Cocker’s One Midsummer’s Day is not just a glorious celebration of swifts but of their place amid the panoply of life on Earth. He takes as his text the John Muir line: ‘When we try to pick out anything by itself, we find it hitched to everything else in the universe.’  Everything is intricately connected – nothing stands alone, particularly not us in our deluded state of Cartesian isolation. Plenty of fellow ecologists make the same point – it should be the creed of our age – but few do so with such deep and wide-ranging knowledge. Cocker is one of our greatest living naturalists, with decades of writing, research and campaigning behind him – and he brings to this vast subject a scientist’s rigour and a poet’s expansive vision.

Swifts sit atop one of the high peaks of evolution, creatures of extraordinary physical prowess. They can spend two years on the wing with only the briefest of landings.